1. Technical Field
This invention relates generally to testing of electronic devices, and more particularly, to contact structure for undertaking tests on circuit boards.
2. Background Art
FIG. 1 illustrates a typical reliability board 20 which includes a number of semiconductor devices inserted in test sockets for testing thereof (one device shown at 22). The board 20 has a portion 20A on which elongated contacts 24 are formed on opposite sides thereof (FIGS. 1 and 2). As is well known, the contacts 24 on one side of the portion 20A are formed in a row, and the contacts on the opposite side of the portion 20A are also formed in a row. The contacts 24 are of highly conductive material, for example gold. The contacts 24 connect to the devices by means of conductive lines (for example conductive lines Ca, Cb connecting device 22 with respective contacts 24).
The portion 20A of the board 20 is insertable into a connector 26 in the direction indicated by the arrow 28. The connector 26 includes a plurality of contacts 29 which engage with respective corresponding contacts 24 on the board portion 20A. The connector 26 is part of a feed though device 30, which includes another connector 32 electrically connected to the connector 26 (FIG. 3).
A control module 34 also has a portion 34A on which elongated contacts 36 are formed on opposite sides thereof, similar to the contacts 24 on the portion 20A of the board 20. This portion 34A of the module 34 is insertable into the connector 32, which includes a plurality of contacts (two shown at 38) which engage with respective corresponding contacts 36 on the module portion 34A. In this way, the control module 34 electrically communicates with the devices on the board 20 and may run through testing cycles for running, for example, High Temperature Operating Life test (HTOL), Highly Accelerated Life Test (HAST), and Write Erase Endurance test (ED) of the devices.
As devices become more complex and the number of devices on board has increased, the number of contacts on the board 20, the control module 34, and the connectors 26, 32 respectively associated therewith has increased substantially. For proper testing to be undertaken, there is a limit in the reduction of contact width (as measured along the elongated edge of for example the portion 20A). This results in the contacts being brought closer and closer together in order in increase contact count. In the event of even a slight misalignment of the board 20 with the connector 26, or the module 34 with the connector 32, improper connection of contacts may be made, resulting in improper signals being provided in testing.
Therefore, what is needed is an approach wherein contact count may be increased, but with it being insured that proper connection of contacts is maintained.